Separation of organic compounds



Hy 25, 1950 LAUER r I 2,516,127

SEPARATION OF ORGANIC COMPOUNDS Filed April 20, 1948 OIL REACTION COOLER Aqueous SYNTHESIS PRODUCT l4 METHANOI- REACTOR 23 i FEED I 1 l2 '3 z L GAS RECYCLE /2 2| J I l u a ['7 I t 2; gm \l 0| L. 123 & VENT-GAS & L E E;

n LIGHT OIL 22 g' I AQUEOUS W 8 c ogfigmc ACIDS PRoDUcT NON-ACID OXYGENATED COMPOUNDS 7 26 d 28 RECYCLE SOLVENT RECYCLE 29 12,3

MIXER 3O V IL CALCIUM SALTS 3f 1; OF h] E ORGANIC ACIDS /52 1/ 4| AQUEOUS c METHANOL 38 5 I NON-ACID SOLVENT w RECYCLE OXYGENATED COMPOUNDS 39 MIXER 40 I FILTER I w Y REC v 50 /5| 45 y (z I z 2 SE a: E r I I: 46 3 47 49 m 54 E 55 SODIUM SALTS 0F ORGANIC ACIDS INVENTORS GEORGE G. LAUER ATTORNEYS Pai 'n Jilly 1 UNITED STATES PATENT OFFICE SEPARATION OF ORGANIC COMPOUNDS George G. Lauer, New York, N. Y., and Herbert J. Passino, Englewood, N. .L, asslznors to The M. W. Kellogg Company, Jersey City, N. 1., a corporation oi Delaware Application April 20, 1948, Serial No. 22,108

28 Claims. '(Cl. 260-450) Other objects and advantages inherent in the invention will be apparent from the following more detailed disclosure.

In a prior and copending application (Serial No. 12,524, filed March 2, 1948) it was disclosed that when mixtures of water-insoluble C4 and higher hydrocarbons, organic acids, and other non-acid oxygen-ated compounds (which may comprise alcohols, aldehydes, ketones and esters) are contacted with an oxide, hydroxide, or carbonate of the alkaline earth metals comprising calcium, barium or magnesium, substantially all of the acids present in the mixture are converted to their corresponding alkaline earth salts, and

phase produced in processes for the catalytic hy- 16 o p p s of e e Salts are obtained. y drogenation of oxides of carbon. reason of the non-acid components in the mix- It is well known that water-insoluble organic ore h ving an unexpected solvent power for the acids can be partially recovered from mixtures formed alkaline earth salts of the organic acids, containing them and water-insoluble non-acid thus keeping these Solis in Solution- Upon suboxygenated organic compounds, by neutralizing 20 lo g the resulting mixture to phase separation, the acids contained in these mixtures with an there s obtained a pp p a which comalkali, such as sodium hydroxide or potassium p e the major Portion of non-acid oxygenated hydroxide, to obtain an aqueous solution of their compounds and hydrocarbons present, and a lowcorresponding alkali salts. These salts may be Phase Which comprises the remaining p on ne'xt separated from the remaining oxygenated of the mixture containing the aforementioned compounds by conventional means, such as disalkaline earth salts of the acids. This lower phase t n t of non..acid m t or water-washing material is next treated with an alkali, such as of the salts which are then treated with an in- Sodium ydr or Potassium y d in an organic acid t obtain t corresponding free amount sufilcient to convert the alkaline earth organic acids. It has been found, however, that salts to their corresponding alkali salts and to the use of these alkalis in the above-mentioned form y i'i 0f the alkaline earth metal. processes, results in the formation of salts of or- The formed hydroxide s then separated from ganic acids which have strongsolutizing properother components Present in the mixture. by fi ties for non-acid chemicals present in the mixs. centrifuging o other Similar S p a on ture, and thus render the subsequent separation f The lower Phase m l s also contactof these salts extremely difl'icult. ed with o aq o lution of a water-soluble It is, therefore, an object of this invention to alcoholin an amount fl o ent to absorb subprovide an improved method for separating stantially all of the alkali salts of organic acids ter-insoluble organic acids as their corresponding P While on-acid oxy enat d o pounds alkali salts, from mixtures containing these acids 40 and hydrocaibons Present in s lower phase are and other waterdngoluble non-acid oxygenated extracted Wltl'l a water -insoluble organic comorganic compounds pound, such as a hydrocarbon having from 5 to Another object of the invention is to provide 12 carbonetoms per molecule The lower p e an improved method for separating watebinmaterial is contacted with the aforementioned soluble organic acids astheir corresponding alkali alkali alcohol and hydrocarbon treating agents salts, from a i t of waterqnsoluble oxygeneither as a mixture of the three treating agents, ated organic compounds containing these acids as a mixture of any tWo ng agents foland non acid oxygenated organic compounds lowed by treatment the treating agent, comprising alcohols, aldehydes, ketones and esas Successive treating Steps mp ying each ters, wherein this mixture is obtained from a hy- 5 the afOrementioned treating agents in any drocarbon-rich phase produced in processes for desired orderthe catalytic hydrogenation of oxides of carbon Following the above-mentioned removal of th and wherein each of the oxygenated compounds formed hydroxide of the alkaline earth metal, present in the mixture has at least 4 carbon atoms the treated lower phase material is subjected to per molecule. as phase separation to obtain an upper phase comprising the hydrocarbon treating agent and nonacid oxygenated compounds and hydrocarbons, and a lower phase comprising the aforementioned alkali salts and the aqueous solution of the alcohol treating agent. The hydrocarbon-treating agent is subsequently stripped from non-acid oxygenated compounds and hydrocarbons in the last-mentioned upper phase and may be recycled for further use. Similarly, the alcohol treating agent is stripped from the alkali salts of the acids resent in the last-mentioned lower phase and may also be recycled for further use; The separated alkali salts may then be recovered and work-up in any conventional manner known to those skilled in the art; for example, they may be treated with a strong mineral acid for converting these salts to their corresponding free organic acids, which may be separated from the remaining water by gravity settling.

As indicated above, when the aforementioned mixtures of water-insoluble C4 and higher hydrocarbons, organic acids and other water-insoluble non-acid oxygenated organic compounds are contacted with the aforementioned compounds of the alkaline earth metals, and subjected to phase separation, there is obtained an upper phase comprising the major portion of non-acid oxygenated compounds and hydrocarbons and a lower phase comprising the remaining portion of non-acid compounds and the formed alkaline earth salts of the acids. We have found, however, that where a, mixture of the aforementioned C4 and higher water-insoluble organic acids and C4 and higher water-insoluble non-acid oxygenated organic compounds, does not contain the aforementioned hydrocarbons, a similar phase separation between nonacid chemicals and formed alkaline earth salts of the acids is not achieved after treatment with the aforementioned compounds of the alkaline earth metals. This condition is encountered by reason of a portion of the non-acid oxygenated compounds having a strong solubility for the alkaline earth salts of the acids, so that the addition of one or more of the aforementioned compounds of the alkaline earth metals to the aforementioned mixture of water-insoluble compounds, results in no precipitation of the alkaline earth salts of the acids which could be converted to their corresponding alkali salts, upon subsequent stratification, for easier acid recovery.

In order to efiect the aforementioned precipitation of the alkaline earth salts of the acids so that subsequent phase separation between them and non-acid oxygenated compounds may be obtained, we have found that the prior addition of certain low-boiling solvents to mixtures of water-insoluble organic acids and water-insoluble non-acid oxygenated organic compounds (each of the compounds having 4 or more carbon atoms per molecule) results in the aforementioned precipitation taking place, upon subsequent treatment with one or more of the aforementioned compounds of the alkaline earth metals, as fully hereinafter described. The addition of the aforementioned low-boiling solvent results in the formation of a two-phase system, the upper phase containing the major portion of oxygenated compounds (substantially free of acids or acid salts) dissolved in the solvent, while the lower phase contains substantially all of the acids present in the original mixture, in the form of their corresponding alkaline earth salts and the remainder of the oxygenated compounds. Upon subsequent stratification, this lower phase is worked-up by converting these salts to their corresponding alkali salts, followed by subjecting this phase to double extraction with an aqueous solution of an alcohol and a hydrocarbon as treating agents, according to the procedure indicated in the aforementioned application (Serial No. 12,524) as more fully hereinafter described.

The low-boiling solvent used as a precipitating agent in the aforementioned initial treatment of the mixture of water-insoluble organic acids and non-acid oxygenated organic compounds, is a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule, such as a hydrocarbon, or a mixture of saturated and unsaturated hydrocarbons, or an oxygencontaining organic compound such as an ether, or a ketone, or the like, as more fully hereinafter described.

We have found that the aforementioned procedure has a particular applicability, although not restricted thereto, when applied to the separation of water-insoluble organic acids from mixtures containing them and non-acid oxygenated organic compounds, obtained as extracts from a hydrocarbon-rich phase produced in processes for the catalytic hydrogenation of oxides of carbon, wherein each of the oxygenated compounds present in the mixture has at least 4 carbon atoms per molecule.

The accompanying drawing illustrates diagrammatically one form of the apparatus employed and capable of carrying out one embodiment of the process of the present invention. While the invention will be described in detail by reference to the embodiment of the process employing the apparatus illustrated in the drawing, it should be noted that it is not intended that the invention be limited thereto, but is capable of other embodiments which may extend beyond the scope of the apparatus illustrated. Some of the mechanical elements necessary to effect the transfer of liquids and vapors and to maintain the conditions of temperature and pressure necessary to carry out the function of the apparatus, are omitted in order to simplify the description. It will be understood, however, that much equipment of this nature is necessary and will be supplied by those skilled in the art. In

addition, it should be noted that while in the embodiment illustrated and described, a hydrocarbon-rich phase obtained from the condensation of the reaction product produced in the catalytic hydrogenation of oxides of carbon, is presented as the feed-stock mixture from which the aforementioned mixture of organic acids and non-acid oxygenated organic compounds is to be separated for subsequent treatment, this feedstock mixture may also comprise any mixture of water-insoluble organic acids and water-insoluble non-acid oxygenated organic compounds and hydrocarbons obtained from any source, wherein each compound has at least 4 carbon atoms per molecule and wherein the aforementioned components of the mixture are present in any ratio.

Referring to the drawing, a synthesis feed comprising a reaction mixture of hydrogen and an oxide of carbon, at varyin mol ratios such as 2: is supplied through line l0 and transferred through this line to a synthesis reaction vessel represented in the drawing by reactor I i In reactor II the reaction mixture is contacted with a hydrogenation catalyst such as a reduced iron or cobalt catalyst at temperatures varying between about 300 F. and about 700 F. and at pressures varying between about atmospheric pressure and stantia lly asit comes from the reactor within the.

aforementioned" temperature range, containing water, hydrocarbons and :oxygenated organic compounds comprising aldehydes, ketones, esters, acids and alcohols and is first cooled to condense substantially large quantities of normally-liquid components. Conveniently, condensation may be efiected in a plurality of cooling stages, which are represented diagrammatically in the drawing by cooler IS with which line l2 connects. From cooler I3, the resulting mixture of condensate and uncondensed gases pass through line I4 to a separator [5. In the latter, uncondensed gases are withdrawn through line It and recycled through this line to the synthesis feed in line It, with which line It connects. Vent-gas and uncondensed light oil may be withdrawn through line [1. The condensate in separator l5 separates as The resulting reaction product a lower aqueous phase and an upper oil phase.

The aqueous phase is drawn off from the bottom of separator through line l8 for further use or treatment outside the scope of the present process, and the oil phase is drawn at an intermediate point through line 19. It should be noted that apparatus employing more than one separation stage may be employed, if desired; for example primary and secondary stages may be introduced, operating successively and respectively at temperatures of about 150 F. and about 100 F.

The oil product liquid phase withdrawn from separator l5 through line l9, comprises a hydrocarbon-rich mixture containing water-insoluble C4 and higher hydrocarbons and organic acids and may also comprise other C4 and higher waterinsoluble oxygenated organic compounds, such as alcohols, aldehydes, ketones and esters. This hydrocarbon mixture in line I9 is next subjected to extraction treatment with a hydrocarbon-insoluble alcohol treating agent having not mor than three carbon atoms per molecule such as methanol, ethanol or propanol, to extract the aforementioned oxygenated compounds from the oil. the particular alcohol treating agent selected having a boiling point lower than that of the oxyenated compounds subjected to extraction. For this purpose, the aforementioned hydrocarbonrich mixture is transferred through line l9 to a low point in an extraction tower 20. In tower the mixture introduced through line I9 is subjected to intimate counter-current contact with one or more of the aforementioned hydrocarboninsoluble alcohol treating agents, such as methanol or an aqueous solution of methanol, which is introduced into tower 20 through line 2|. The methanol treating agent and the mixture of hydrocarbons and oxygenated organic compounds are contacted in tower 20 under conditions effective to absorb in the methanol substantially all of the oxygenated organic compounds present. The extract thus produced, comprising a mixture of the methanol treating agent and other oxygenated organic compounds namely, aldehydes, ketones, esters, acids and alcohols, is withdrawn from the bottom of tower 20 through line 22. The separated hydrocarbon or oil layer in tower 20 is withdrawn overhead through line 23 for further use or treatment outside the scope of the present process.

In order to recover the methanol treating agent, or anyhydrocarbon-insoluble alcohol used as a treating agent, from the extract withdrawn from tower 20, this extract is next transferred via line 22 toastripper 24. Stripper 24 is operated under conditions of temperature-and pressure effective to distill overhead the methanol treating agent, which is withdrawn-through line 2| and recycled through thisline for further use as the treating agent in tower520: -Ma.keup methanol is intro duced into line 2| through line.25,,-with which line 2| connects. Bottoms from stripper 24 com prising a mixture of organic acids, alcohols, aldehydes, ketones and esters, each of these com pounds having at least 4 carbon atoms permolecule, are withdrawn through line 26 as the feed from which the aforementioned C4 and organic acids are to be separated as their corresponding alkali salts from other non-acid C4 and higher oxygenated compounds present, in accordance with the process of the invention hereinafter described. At this point, it should be noted that it is possible to introduce a similar mixture of the aforementioned water-insoluble acids and nonacid oxygenated compounds as the feed through line 26, in instances where this mixture is obtained from sources other than as an extract from a hydrocarbon-rich phase produced in processes for the catalytic hydrogenation of oxides of carbon.

The mixture of the aforementioned C4 and higher organic acids and non-acid oxygenated compounds in line 26 is next contacted in a mixer 21, with one or more compounds selected from the group consisting of the oxides, hydroxides and carbonates of the alkaline earth metals comprising calcium, barium and magnesium in a solid or liquid form-calcium oxide being representative of the aforementioned compounds of the above named alkaline earth metals. The compound thus used is introduced into mixer 21 through line 28, in an amount suificient to convert substantially all of the acids present, into a solution of their alkaline earth salts, i. e., to the calcium salts of the acids, in the embodiment illustrated.

After complete admixture of the aforementioned reactants has taken place in mixer 21, the resulting mixture comprising calcium salts of the organic acids and non-acid oxygenated organic compounds is transferred through line 29 to a mixer 30. In order to effect precipitation of the aforementioned calcium salts of the acids so that subsequent phase separation between them and non-acid chemicals may be obtained, a relatively low-boiling solvent, comprising a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule, is introduced into mixer 30 through valved line 3| as a precipitating agent. This precipitating agent, as previously described, may be a hydrocarbon such as pentane, hexane or heptane, or a saturated hydrocarbon fraction boiling between about 30 C. and about 50 C., or a mixture of saturated and unsaturated hydrocarbons boiling between 'about 30 C. and about 60 C., which meet the above requirements. In addition, it. is possible to use an oxygen-containing organic compound such as relatively low boiling ethers (e. g., ethyl ether or di-isopropyl ether), ketones (e. g., acetone) or the like, as precipitating or first-treating agents.

After complete admixture of the aforementioned reactants has taken place in mixer 30, the resulting mixture comprising calcium salts of the organic acids, non-acid oxygenated compounds, and the precipitating agent is transferred through line 32 to a separator 33. In separator 33 the aforementioned mixture is permitted to settle for a period of time sumcient to efiect substantially complete separation into an upper phase which comprises the major portion of oxygenated compounds (substantially free of acids or acid salts) dissolved in the solvent or precipitating agent and any excess quantities of the solvent, and a lower phase which comprises the aforementioned calcium salts of organic acids and the remaining portion of non-acid oxygenated compounds. The upper phase from separator 33 is withdrawn through line 34, while the lower phase is withdrawn through line 35.

The upper phase from separator 33, comprising a mixture of the major portion of oxygenated organic compounds (acid-free) dissolved in the aforementioned solvent is transferred through line 34 to a stripper 3i. Stripper 36, is operated under conditions of temperature and pressure effective to distill overhead the aforementioned solvent treating agent, which is withdrawn through line 31 and recycled through this line to combine with the solvent treating agent feed in line 3| with which line 31 connects. Bottoms from stripper 35, comprising non-acid oxygenated organic compounds, are withdrawn through line 38 for further use or treatment outside the scope of the present process.

The lower phase material in line 35 is next transferred through this line into a mixer 35, where it is contacted with an alkali in an amount sufllcient to convert substantially all of the calcium salts of the acids to their corresponding alkali salts, although it has been found desirable to introduce the alkali in an excess of about 10%. For this purpose, such alkalis as sodium hydroxide or potassium hydroxide (the former being employed in the embodiment illustrated in the drawing), either in the solid form or in aqueous solutions, are introduced into mixer 39 through valved-line 40, to form the corresponding sodium salts of the acids and the hydroxide of the alkaline earth metal, namely, calcium hydroxide. The mixture in mixer 39 is also contacted with an aqueous solution of a water-soluble alcohol, in an amount suflicient to absorb substantially all of the sodium salts of organic acids present. This aqueous solution of the alcohol treating agent may comprise an aqueous solution of methanol, ethanol or propanol, in an alcohol to water ratio of approximately 1:1, while the preferred quantities of the alcohol solution employed may be two or three times, volumetrically that of the total mixture comprising the aforementioned lower phase present in line 35. This aqueous solution of the alcohol treating agent, such as methanol, is also introduced into mixer 39, through line 40.

In order to facilitate the subsequent separation of the non-acid oxygenated compounds present in the aforementioned mixture in line 35, this mixture is also contacted with a substantially water-insoluble organic compound having from to 12 carbon atoms per molecule, in an amount suflicient to absorb substantially all of the non-acid material present and is introduced into mixer 39 through valved-line 4|. This treating agent, or second solvent, may comprise any of the aforementioned treating agents used as the solvent in mixer 30, of the types hereinbefore described. In this respect, it will be noted that while this second treating agent may be either a hydrocarbon or an oxygen-containing compound, similar to that used as a first treating agent in mixer 34, it is preferred to use a hydrocarbon such as pentane, hexane or heptane, as

the second treating agent; on the other hand. there is no particular preference in the use of either a hydrocarbon or an oxygen-containing compound as the first treating agent. It should be also mentioned at this point, that while identical treating agents may be used as the aforementioned first and second treating agents, it has been found that it is impossible to use an excess of the first treating agent in mixer 3| in order to eliminate the necessity of using additional quantities of this treating agent in mixer 39, by reason that such excess quantities of the first treating agent tends to remain in the upper phase in separator 33, and hence are not carried over with the material present in the lower phase.

As previously indicated, the lower phase material in line 35 is contacted with the aforementioned alkali and alcohol treating agents as a mixture of the aqueous solution of the alcohol treating agent and the alkali, which are introduced into mixer 39 through line 40, and the second treating agent which is introduced through line 4|. However, if so desired, it is possible to introduce all three treating agents into mixer 39, simultaneously or successively, through one line such as line 40; or a mixture of any two of the treating agents may be introduced through one line, followed by the introduction of the third treating agent through another line.

After complete admixture has taken place in mixer 35, the resulting mixture (comprising sodium salts of organic acids absorbed in the alcohol treating agent, non-acid oxygenated compounds absorbed in the hydrocarbon or second treating agent, and calcium hydroxide), is transferred through line 42 to a filter, filter-press, centrifuge or other similar separation media, represented in the drawing by filter 43, to separate the formed calcium hydroxide from other components present in the mixture. Calcium hydroxide thus separated is withdrawn from filter 43 through line 44 and thus recycled to the calcium oxide feed in line 28, with which line 44 connects.

Following the aforementioned removal of the formed hydroxide of the alkaline earth metal, i. e., calcium hydroxide, the remainder of the mixture in filter 43 is withdrawn through line 45. This mixture is next transferred through this line to a separator 46. In separator 46 the mixtrn'e is permitted to settle for a period of time suflicient to eifect substantially complete separation of the components into an upper phase, which comprises a mixture of non-acid oxygenated compounds absorbed in the hydrocarbon or second treating agent, which is withdrawn through valved-line 41, and a lower phase which comprises a mixture of the sodium salts of organic acids and the aqueous solution of the alcohol treating agent, which is withdrawn through line 48.

The upper'phase from separator 46, comprismg a mixture of non-acid oxygenated compounds absorbed in the hydrocarbon treating agent is transferred through line '41 to a stripper 49. Stripper 49 is operated under conditions of temperature and pressure eifective to distill overhead the hydrocarbon-treating agent, which is withdrawn through line 50 and recycled through this line to combine with the hydrocarbon treating-agent feed in line 4 I, with which line 5| connects. Bottoms from stripper 49, comprising non-acid oxygenated organic compounds, are withdrawn through line SI and may becombincd with the non-acid oxygenated compounds withdrawn from stripper 35 through line 38, for further use or treatment outside the scope of the present process. At this point, it will be noted that where the aforementioned first and second treating agents are identical, it is possible to transfer the upper phase from separator 46, via line 41, into valved-line 52 for subsequent stripping of the second treating agent in stripper 36, via line 34, thus eliminating the necessity for a second piece of equipment, namely, stripper 49.

The lower phase in separator 46, comprising a mixture of the aforementioned sodium salts of organic acids and the aqueous solution of the alcohol treating agent (methanol, in the embodiment illustrated), is transferred through line 48 to a stripper 53. Stripper 53 is operated under conditions of temperature and pressure effective to distill overhead the alcohol treating agent, which is withdrawn through line 54 and recycled through this line to combine with the alcohol treating-agent feed in line 40, with which line 54 connects. Bottoms from stripper 53, comprising an aqueous solution of the sodium salts of organic acids, are withdrawn through line 55. These separated alkali salts may be next workedup in any conventional manner known to those skilled in the art, for example, treating them with a strong mineral acid such as sulfuric acid or hydrochloric acid to convert these salts to their corresponding free organic acids.

The following specific examples will serve to illustrate but are not intended in any way to limit unduly the broad scope of the invention.

Example I 1000 gm. of a mixture of oxygenated compounds (obtained by extraction from the waterinsoluble product produced in the catalytic hydrogenation of carbon monoxide, followed by stripping of the extracting agent), containing C4 and higher water-insoluble organic acids, alcohols, aldehydes, ketones, and esters, was neutralized under cooling with a concentrated slurry of calcium oxide in water (containing 1'70 gm. of dry calcium oxide), until a pH of 8.5 was reached. To this mixture was added 3300 gm. of di-ethyl ether and the resulting two liquid phases separated by centrifuging. The upper layer was stripped of solvent, and 495 gm. of an oil were obtained, substantially free of acids and containing the major part of alcohols, aldehydes,

ketones, and esters present in the starting material. The lower viscous phase, comprising substantially all acids in the form of their calcium salts and the remaining portion of non-acid oxygenated compounds, was next treated in a mixer with 1500 gm. of an aqueous solution of methanol (1:1) which contained sodium hydroxide in a 10% excess of the calcium oxide previously employed in the neutralization step. Simultaneously, 1200 gm. of pentane were added. The entire mixture was next passed through a filter to remove calcium hydroxide and then subjected to gravity settling. The resulting upper layer was found to be substantially free from any salts of organic acids and was next stripped of pentane. gm. of pentane-free oil thus obtained were combined with the oil from the upper layer of the centrifuging step, thus representing 550 gm. of acid-free material. The remaining lower layer from the gravity settling step was stripped of methanol and. acidified with sulfuric acid, whereupon 445 gm. of free'organic acids were obtained as a result of the treatment.

Example I! To 1000 gm. of the mixture employed in Example I were added 3800 gm. of hexane and the mixture neutralized with gm. of dry calcium oxide'under cooling. The resulting two phases were separated by gravity settling and the lower viscous phase treated with 1400 gm. of an aqueous solution of ethanol 1:1) which contained sodium hydroxide in a 10% excess of the calcium oxide previously employed in the neutralization step. After removing calcium hydroxide by filtration, the mixture was next extracted with 1000 gm. of hexane. The extract was combined with the upper layer from the first gravity settling and the hexane stripped. 550 gm. of an oil were obtained comprising the non-acid oxygenated compounds of the starting material substantially free of salts of organic acids. The alcoholic layer from the extraction step was stripped of alcohol and acidified, whereupon 445 gm. of organic acids were obtained.

We claim:

1. A method for separating organic acids as their corresponding alkali salts from a mixture of water-insoluble oxygenated organic compounds comprising said acids and non-acid oxygenated compounds wherein each of the compounds present in the mixture has at least 4 carbon atoms per molecule, which comprises the steps of contacting said mixture with at least one compound selected from the group consisting of the oxides, hydroxides and carbonates of the alkaline earth metals comprising calcium, barium, and magnesium in an amount sufficient to convert substantially all of said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a first solvent treating agent in an amount suflicient to precipitate said alkaline earth salts from non-acid oxygenated compounds, separating the resulting mixture into an upper phase comprising a major portion of said non-acid oxygenated compounds and said first solvent treating agent and a lower phase comprising said alkaline earth salts and the re maining portion of said non-acid oxygenated compounds, separating said first solvent treating agent and non-acid oxygenated compounds from said upper phase, contacting said lower phase with an alkali in an amount sufiicient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide of said alkaline earth metal, contacting said lower phase with an aqueous solution of a water-soluble alcohol treating agent in an amount suflicient to absorb substantially all of said alkali salts, contacting said lower phase with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a second solvent treating agent in an amount suflicient to absorb substantially all of said remaining portion of non-acid oxygenated compounds, separating said formed hydroxide of said alkaline earth metal from the resulting mixture, separating the remainder of said lastmentioned mixture into an upper phase comprising said remaining portion of non-acid oxygenated compounds and said second solvent treating agent and a lower phase comprising said alkali salts and said alcohol treating agent, separating said second solvent treating agent and non-acid oxygenated compounds from said upper phase, separating said alcohol treating agent and alkali salts from said last-mentioned lower phase,

and recovering said alkali salts as a product oi the process.

2. A method for separating organic acids as their corresponding alkali salts from a mixture of water-insoluble oxygenated organic compounds comprising alcohols, aldehydes,. ketones, esters and acids wherein each of the compounds present in the mixture has at least 4 carbon atoms per molecule which comprises the steps of contacting said mixture with at least one compound selected from the group consisting of the oxides, hydroxides and carbonates of the alkaline earth metals comprising calcium, barium and magnesium in an amount suflicient to convert substantially all of said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a first solvent treating agent in an amount sufiicient to precipitate said alkaline earth salts from non-acid oxygenated compounds, separating the resulting mixture into an upper phase comprising a major portion of said non-acid oxygenated compounds and said first solvent treating agent and a lower phase comprising said alkaline earth salts and the remaining portion of said non-acid oxygenated compounds, separating said first solvent treating agent and non-acid oxygenated compounds from said upper phase, contacting said lower phase with an alkali in an amount suflicient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide of said alkaline earth metal, contacting said lower phase with an aqueous solution of a water-soluble alcohol treating agent in an amount suflicient to absorb substantially all of said alkali salts, contacting said lower phase with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a second solvent treating agent in an amount sufilcient to absorb substantially all of said remaining portion of non-acid oxygenated compounds, separating said formed hydroxide of said alkaline earth metal from the resulting mixture, separating the remainder of said last-mentioned mixture into an upper phase comprising said remaining portion of non-acid oxygenated compounds and said second solvent treating agent and a lower phase comprising said alkali salts and said alcohol treating agent, separating said second solvent treating agent and non-acid oxygenated compounds from said upper phase, separating said alcohol treating agent and alkali salts from said last-mentioned lower phase, and recovering said alkali salts as a product of the process.

3. The method of claim ,2 wherein the compound of said alkaline earth metals is calcium oxide.

4. The method of claim 2 wherein the compound of said alkaline earth metals is calcium hydroxide.

5. The method of claim 2 wherein the compound of said alkaline earth metals is barium oxide.

6. The method of claim 2 wherein the compound of said alkaline earth metals is magnesium oxide.

'7. The method oi claim 2 wherein the compound of said alkaline earth metals is magnesium hydroxide.

8. The method of claim 2 wherein said first solvent treating agent is an oxygen-containin compound.

15. The method or claim 2 wherein said alkali 4 is potassium hydroxide.

16. The method of claim 2 wherein said alkali is sodium hydroxide.

17. The method of claim 2 wherein the watersoluble alcohol treating agent comprises an aqueous mixture having an alcohol-water ratio of 1:1.

18. The method of claim 17 wherein the alcohol treating agent is methanol.

19. The method of claim 17 wherein the alcohol treating agent is ethanol.

20. The method of claim 17 wherein the alcohol treating agent is propanol.

21. In a process for the catalytic hydrogenation of an oxide of carbon in which is obtained a hydrocarbon-rich phase containing a mixture of oxygenated organic compounds comprising acids and non-acid oxygenated compounds, each of said hydrocarbons and oxygenated compounds having at least 4 carbon atoms er molecule, and wherein said mixture of oxygenated compounds is extracted from said hydrocarbon-rich phase with an aqueous solution of an alcohol treating agent having not more than 3 carbon atoms per molecule and wherein said mixture of oxygenated compounds is separated from said treating agent, the method of recovering acids as their corresponding alkali salts from the mixture of oxygenated compounds thus obtained which comprises the steps of contacting said mixture with at least one compound selected from the group consisting of the oxides, hydroxides and carbonates oi the alkaline earth metals comprising calcium, barium and magnesium in an amount suflicient to convert substantially all 01' said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substan tially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a first solvent treating agent in an amount sufficient to precipitate said alkaline earth salts from non-acid oxygenated compounds, separating the resulting mixture into an upper phase comprising a major portion of said non-acid oxygenated compounds and said first solvent treating agent and a lower phase comprising said alkaline earth salts and the remaining portion of said non-acid oxygenated compounds, separating said first solvent treating agent and nonaoid oxygenated compounds from said upper phase, contacting said lower phase with an alkali in an amount sufilcient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide oi said alkaline earth metal, contacting said lower phase with an aqueous solution of a watersoluble alcohol treating agent in an amount sufflcient to absorb substantially all of said alkali salts, contacting said lower phase with a substantially water insoluble organic compound having from 5 to 12 carbon atoms per molecule as a second solvent treating agent in an amount 7 sumcient to absorb substantially all oi. said repounds and said second solvent treating agent and a lower phase comprising said alkali salts and said alcohol treating agent, separating said second solvent treating agent and non-acid oxygenated compounds from said upper phase, separating said alcohol treating agent and alkali salts from said last-mentioned lower phase, and recovering said alkali salts as a product of the process.

22. In a process for the catalytic hydrogenation of an oxide of carbon in which is obtained a hydrocarbon-rich phase containing a, mixture of oxygenated organic compounds comprising alcohols, aldehydes, ketones, esters and acids, each of said hydrocarbons and oxygenated compounds having at least four carbon atoms per molecule, and wherein said mixture of oxygenated compounds is extracted from said hydrocarbon-rich phase with an aqueous solution of an alcohol treating agent having not more than three carbon atoms per molecule and wherein said mixture of oxygenated compounds is separated from said treating agent, the method of recovering acids as their corresponding alkali salts from the mixture of oxygenated compounds thus obtained which comprises the steps of contacting said mixture with at least one compound selected from the group consisting'of the oxides, hydroxides and carbonates of the alkaline earth metals comprising calcium. barium and magnesium in an amount suflicient to convert substantially all of said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substantially water-insoluble organic compound having from to 12 carbon atoms per molecule as a first solvent treating agent in an amount sufilcient to precipitate said alkaline earth sa ts from non-acid oxygenated compounds, seperating the resulting mixture into an upper phase comprising a major portion of said non-acid oxygenated compounds and said first solvent treating agent and a lower phase comprising said alkaline earth salts and the remaining portion of said non-acid oxygenated compounds, separating said first solvent treating agent and non acid oxygenated compounds from said upper phase, contacting said lower phase with an a kali in an amount suiilcient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide of said alkaline earth metal, contacting said lower phase with an aqueous solution of a watersoluble alcohol treating agent in an amount sufficient to absorb substantially all of said alkali salts, contacting said lower phase with a substantially water-insoluble organic compound having from'5 to 12 carbon atoms per molecule as a second solvent treating agent in an amount sufficient to absorb substantially all of said remaining portion of non-acid oxygenated compounds, separating said formed hydroxide of said alkaline earth metal from the resulting mixture, separating the remainder of said last-mentioned mixture into an upper phase comprising said remaining portion of non-acid oxygenated compounds and said second solvent treating agent and a, lower phase comprising said alkali salts and said alcohol treating agent, separating said second solvent treating agent and non-acid oxygenated compounds from said upper phase, separating said alcohol treating agent and alkali salts from said last-mentioned lower phase, and recovering said alkali salts as a product of the process.

23. A method for separating organic acids as their corresponding alkali salts from a mixture of water-insoluble oxygenated organic compounds comprising said acids and non-acid oxygenated compounds wherein each of the compounds present in the mixture has at least 4 carbon atoms per molecule, which comprises the steps of contacting said mixture with at least one compound selected from the group consisting of the oxides, hydroxides and carbonates 0f the alkaline earth metals comprising calcium, barium, and magnesium in an amount suiiicient to convert substantially all of said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a first solvent treating agent in an amount suiiicient to precipiate said alkaline earth salts from non-acid oxygenated compounds, separating the resulting mixture into an upper phase comprising a major portion of said non-acid oxygenated compounds and said first solvent treating agent and a lower phase comprising said alkaline earth salts and the remaining portion of said non-acid oxygenated compounds, contacting said lower phase with an alkali in an amount suflicient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide of said alkaline earth metal, contacting said lower phase with an aqueous solution of a water-soluble alcohol treating agent in an amount sufiicient to absorb substantially all of said alkali salts, contacting said lower phase with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a second solvent treating agent in an amount sufiicient to absorb substantially all Of said remaining portion of non-acid oxygenated compounds, separating said formed hydroxide of said alkaline earth metal from the resulting mixture, separating the remainder of said last-mentioned mixture into an upper phase comprising said remaining portion of non-acid oxygented compounds and said second solvent treating agent and a lower phase comprising said alkali salts and said alcohol treating agent, separating said alcohol treating agent and alkali salts from said last-mentioned lower phase, and recovering said alkali salts as a product of the process.

24. A method for separating organic acids as their corresponding alkali salts from a mixture of water-insoluble oxygenated organic compounds comprising alcohols, aldehydes, ketones, esters and acids wherein each of the compounds present in the mixture has at least 4 carbon atoms per molecule which comprises the steps of contacting said mixture with at least one compound selected from the the group consisting of the oxides, hydroxides and carbonates of the alkaline earth metals comprising calcium, barium and magnesium in an amount sufiicient to convert substantially all of said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substantially waterinsoluble organic compound having from 5 to 12 carbon atoms per molecule as a first solvent treating agent in an amount sufficient to precipitate said alkaline earth salts from non-acid oxygenated compounds, separating the resulting mixture into an upper phase comprising a major portion of said non-acid oxygenated compoimds and said first solvent treating agent and a lower phase comprising said alkaline earth salts and the remaining portion of said non-acid :oxygenated compounds, contacting said lower phase with an alkali in an amount suiiicient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide of said alkaline earth metal, contacting said lower phase with an aqueous solution of a water-soluble alcohol treating agent in an amount suflicient to absorb substantially all of said alkali salts, contacting said lower phase with a substantially water-insoluble organic compound having from to 12 carbon atoms per molecule as a second solvent treating agent in an amount suflicient to absorb substantially all of said remaining portion of non-acid oxygenated compounds, separating said formed hydroxide of said alkaline earth metal from the resulting mixture, separating the remainder of said last-mentioned mixture into an upper phase comprising said remaining portion of non-acid oxygenated compounds and said second solvent treating agent and a lower phase comprising said alkali salts and said alcohol treating agent, separating said alcohol treating agent and alkali salts from said last-mentioned lower phase, and recovering said alkali salts as a product of the process.

25. A method for separating carboiwlic organic acids as their corresponding alkali salts from a mixture of water-insoluble oxygenated organic compounds comprising said acids and non-acid oxygenated compounds wherein each of the compounds present in the mixture has at least 4 carbon atoms per molecule, which comprises the steps of contacting said mixture with at least one compound selected from the group consisting of the oxides, hydroxides and carbonates of the alkaline earth metals comprising calcium, barium, and magnesium in an amount suflicient to convert substantially all of said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substantially water-insoluble organic compound having from5 to 12 carbon atoms per molecule as a first solvent treating agent in an amount sufilcient to precipitate said alkaline earth salts from nonacid oxygenated compounds, separating the resulating mixture into an upper phase comprising a major portion of said non-acid oxygenated compounds and said first solvent treating agent and a lower phase comprising said alkaline earth salts and the remaining portion of said non-acid oxygenated compounds, contacting said lower phase with an alkali in an amount suflicient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide of said alkaline earth metal,

contacting said lower phase with an aqueous solution of a water-soluble alcohol treating agent in an amount suflicient to absorb substantially all of said alkali salts, contacting said lower phase with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a second solvent treating agent in an amount sufficient to absorb substantially all of said remaining portion of non-acid omgenated compounds, separating said formed hydroxide of said alkaline earth metal from the resulting mixture, separating the remainder of said last-mentioned mixture into an upper phase comprising said remaining portion of non-acid oxygenated compounds and said second solvent treating agent 16 and said alcohol treating agent, separating said alcohol treating agent and alkali salts from said last-mentioned lower phase, and recovering said alkali salts as a product of the process.

26. A method for separating carboxylic organic acids as their corresponding alkali salts from a mixture of water-insoluble oxygenated organic compounds comprising alcohols, aldehydes, ketones, esters and acids wherein each of the compounds present in the mixture has at least 4 carbon atoms per molecule which comprises the steps of contacting said mixture with at least one compound selected from the group consisting of the oxides, hydroxides and carbonates of the alkaline earth metals comprising calcium, barium and magnesium in an amount suflicient to convert substantially all of said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a first solvent treating agent in an amount suflicient to precipitate said alkaline earth salts from non-acid oxygenated compounds, separating the resulting mixture into an upper phase comprising a major portion of said non-acid oxygenated compounds and said first solvent treating agent and a lower phase comprising said alkaline earth salts and the remaining portion of said non-acid oxygenated compounds, contacting said lower phase with an alkali in an amount sufllcient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide of said alkaline earth metal, contacting said lower phase with an aqueous solution of a water-soluble alcohol treating agent in an amount suilicient to absorb substantially all of said alkali salts, contacting said lower phase with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a second solvent treating agent in an amount suilicient to absorb substantially all of said remaining portion of non-acid oxygenated compounds, separating said formed hydroxide of said alkaline earth metal from the resulting mixture, separating the remainder of said last-mentioned mixture into an upper phase comprising said remaining portion of non-acid oxygenated compounds and said second solvent treating agent and a lower phase comprising said alkali salts and said alcohol treating agent, separating said alcohol treating agent and alkali salts from said last-mentioned lower phase, and recovering said alkali salts as a product of the process.

27. In a process for the catalytic hydrogena- ,tion of an oxide of carbon in which is obtained a hydrocarbon-rich phase containing a mixture of oxygenated organic compounds comprising acids and non-acid oxygenated compounds, each of said hydrocarbons and oxygenated compounds having at least 4 carbon atoms per molecule, and wherein said mixture of oxygenated compounds is extracted from said hydrocarbon-rich phase with an aqueous solution of an alcohol treating agent having not more than 3 carbon atoms per molecule and wherein said mixture of oxygenated compounds is separated from said treating agent, the method of recovering acids as their corresponding alkali salts from the mixture of oxygenated compounds thus obtained which comprises the steps of contacting said mixture with at least one compound selected from the group consisting of the oxides, hydroxides and carbonates of the alkaline earth metals comprising caland a lower phase comprising said alkali salts 15 cium, barium and magnesium in an amount sui- 17 1 ficient to'convert substantially all of said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substantially water-insolubla organic compound having from 5 to 12 carbon atoms per molecule as'a first solvent treating agent in an amount suilicient' to precipitate said alkaline earth salts from nonacid oxygenated compounds, separating the resulting mixture into an upper phase comprising a major portion'of said non-acid oxygenated compounds and said first solvent treating agent and a lower phase comprising said alkaline earth salts and the remaining portion of said non-acid oxygenated compounds, contacting said lower phase with an alkali in an amount sufflcient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide of said alkaline earth metal, contacting said lower phase with an aqueous solution of a water-soluble alcohol treating agent in an amount sumcient to absorb substantially all of said alkali salts, contacting said lower phase with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a second solvent treating agent in an amount suflicient to absorb substantially all of said remaining portion of non-acid oxygenated compounds, separating said formed hydroxide of said alkaline earth metal from the resulting'mixture, separating the remainder of said last-mentioned mixture into an upper phase comprising said remaining portion of non-acid oxygenated compounds and said second solvent treating agent and a lower phase comprising said alkali salts and said alcohol treating agent, separating said alcohol treating agent and alkali salts from said last-mentionad lower phase, and recovering said alkali salts as a product of the process.

28. In a process for the catalytic hydrogenation of an oxide of carbon in which is obtained a hy-' drocarbon-rich phase containing a mixture of oxygenated organic compounds comprising alcohols, aldehydes, ketones, esters and acids, each of said hydrocarbons and oxygenated compounds having at least 4 carbon atoms per molecule, and wherein said mixture of oxygenated compounds is extracted from said hydrocarbon-rich .phase with an aqueous solution of an alcohol treating agent having not more than 3 carbon atoms per molecule and wherein said mixture of oxygenated compounds is separated from said treating agent, the method of recovering acids as their corresponding alkali salts from the mixture of oxygenated compounds thus obtained which coniprises the steps of contacting said mixture with at least one compound selected from the group consisting of the oxides, hydroxides and carbonates oi the alkaline earth metals comprising calcium, barium and magnesium in an amount sufficient to convert substantially all of said acids to a solution of their corresponding alkaline earth salts, contacting said mixture with a substantially water-insoluble organic compound tacting said lower phase with an alkali in an amount sufficient to convert substantially all of said alkaline earth salts to their corresponding alkali salts and to form the hydroxide of said alkaline earth metal, contacting said lower phase with an aqueous solution of a water-soluble alcohol treating agent in an amount suflicient to absorb substantially all of said alkali salts, contacting said lowerphase with a substantially water-insoluble organic compound having from 5 to 12 carbon atoms per molecule as a second solvent treating agent in an amount sufficient to absorb substantially all of said remaining portion of non-acid oxygenated compounds, separating said formed hydroxide of said alkaline earth metal from the resulting mixture, separating theremainder of said last-mentioned mixture into an upper phase comprising said remaining portion of non-acid oxygenated compounds and said second solvent treating agent and a lower phase comprising said alkali salts and said alcohol treating agent, separating said alcohol treating agent and alkali salts from said lastmentioned lower phase, and recovering said alkali salts as a product of the process.

GEORGE G. LAUER. HERBERT J. PASSING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Grahame Oct. 26, 1948 

1. A METHOD FOR SEPARATING ORGANIC ACIDS AS THEIR CORRESPONDING ALKALI SALTS FROM A MIXTURE OF WATER-INSOLUBLE OXYGENATED ORGANIC COMPOUNDS COMPRISING SAID ACIDS AND NON-ACID OXYGENATED COMPOUNDS WHEREIN EACH OF THE COMPOUNDS PRESENT IN THE MIXTURE HAS AT LEAST 4 CARBON ATOMS PER MOLECULE, WHICH COMPRISES THE STEPS OF CONTACTING SAID MIXTURE WITH AT LEAST ONE COMPOUND SELECTED FROM THE GROUP CONSISTING OF THE OXIDES, HYDROXIDES AND CARBONATES OF THE ALKALINE EARTH METALS COMPRISING CALCIUM, BARIUM, AND MAGNESIUM IN AN AMOUNT SUFFICIENT TO CONVERT SUBSTANTIALLY ALL OF SAID ACIDS TO A SOLUTION OF THEIR CORRESPONDING ALKALINE EARTH SALTS, CONTACTING SAID MIXTURE WITH A SUBSTANTIALLY WATER-INSOLUBLE ORGANIC COMPOUND HAVING FROM 5 TO 12 CARBON ATOMS PER MOLECULE AS A FIRST SOLVENT TREATING AGENT IN AN AMOUNT SUFFICIENT TO PRECIPITATE SAID ALKALINE EARTH SALTS FROM NON-ACID OXYGENATED COMPOUNDS, SEPARATING THE RESULTING MIXTURE INTO AN UPPER PHASE COMPRISING A MAJOR PORTION OF SAID NON-ACID OXYGENATED COMPOUNDS AND SAID FIRST SOLVENT TREATING AGENT AND A LOWER PHASE COMPRISING SAID ALKALINE EARCH SALTS AND THE REMAINING PORTION OF SAID NON-ACID OXYGENATED COMPOUNDS, SEPARATING SAID FIRST SOLVENT TREATING AGENT AND NON-ACID OXYGENATED COMPOUNDS FROM SAID UPPER PHASE, CONTACTING SAID LOWER PHASE WITH AN ALKALI IN AN AMOUNT SUFFICIENT TO CONVERT SUBSTANTIALLY ALL OF SAID ALKALINE EARTH SALTS TO THEIR CORRESPONDING ALKALI SALTS AND TO FORM THE HYDROXIDE OF SAID ALKALINE EARTH METAL, CONTACTING SAID LOWER PHASE WITH AN AQUEOUS SOLUTION OF A 